Hijri Calendar
What Is the Hijri Calendar?
The Hijri calendar is a lunar calendar used in Islam that counts years from the Hijra migration in 622 CE. It has 12 months based on the moon cycle.
How lunar months work
Each Hijri month begins with the sighting of the new moon. Because lunar months are about 29.5 days, a Hijri year is about 11 days shorter than the Gregorian year.
Common Hijri month names
The twelve months are Muharram, Safar, Rabi al-awwal, Rabi al-thani, Jumada al-awwal, Jumada al-thani, Rajab, Sha'ban, Ramadan, Shawwal, Dhu al-Qi'dah, and Dhu al-Hijjah. Ramadan is associated with fasting, while Dhu al-Hijjah includes the Hajj season and Eid al-Adha.
How Hijri dates are calculated
Some calendars use a tabular or arithmetic pattern to estimate alternating 29- and 30-day months. Others use astronomical visibility calculations or direct observation of the crescent. A conversion tool can provide a consistent calculated date, but it cannot know which method a local authority will use for an observed religious date.
Why dates shift each year
Because the Hijri calendar is lunar, the same Hijri date moves earlier each Gregorian year. This is why Ramadan and Eid shift by about 10 to 11 days annually.
Convert Hijri dates with confidence
Use the Hijri to Gregorian converter to turn dates into the civil calendar, and read how Hijri and Gregorian calendars differ for full context. Important observances should still be checked locally.